Bonding systems for various types of materials are widely used in different industries. Some of the commonly used methods of bonding various materials together is by use of hot-melt type adhesives. Such hot-melt adhesives are typically applied by means of a hot-gun type device. One of the drawbacks associated with this bonding method is a so-called web/thread formation at the point where traditional hot-melt adhesives are being dispensed. In other words, when the hot-melt adhesive is stopped being dispensed, it will begin to solidify creating a “web” or “thread” that pulls away from the substrate being bonded. This creates both cleanliness and cosmetic issues that are undesirable for various applications.
One of the areas where the bonding systems are commonly used is the field of balloon catheters. The balloon catheters are used for a variety of medical procedures in urology, cardiology, surgery, etc. One of the common ways of attaching a balloon to a catheter shaft and/or for attaching an external woven structure or mesh to the balloon wall is my means of tying the ends of the balloon/mesh with a fiber string, some type of a wrap material or any other similar mechanism. The disadvantage of such bonding approach is that it creates bulky areas at the point of attachment that have a substantially larger diameter than the diameter of the catheter shaft and/or the balloon in its deflated state. This is undesirable for most medical applications, and in particular, for procedures where a balloon catheter needs to be inserted into small bodily cavities and passageways.
Another way of bonding the balloon to the catheter shaft and/or to the mesh is by means of a hot-melt adhesive applied via a hot-gun device to the attachment points. As described above, this approach results in creation of solidified adhesive web/threads and thus, presents issues with cleanliness of the device that require further manufacturing steps to fix. Another problem with this approach is that the hot-melt adhesive may spread to the areas of the balloon and/or mesh where it is undesirable to have the solidified adhesive because it may interfere with the function of the device (e.g., balloon inflation or shape). In order to fix this issue, additional steps of removing the solidified adhesive may be necessary. Removal of excess adhesive from the perimeter of the finished structure with sharps presents severe danger to the integrity of the materials of construction that could result in catastrophic damage to the finished device and, more specifically, to the pneumatic integrity of the balloon.
Accordingly, it is an objective of the present invention to provide a system and method for bonding materials together, and in particular, bonding various layers of a balloon catheter and simultaneously eliminating the steps of adhesive shaping and removal, that overcomes the disadvantages of the prior art methods and systems described above. It is also an objective of the present invention to provide a bonding system that provides for a uniform pressure-flow of hot-melt adhesive and simultaneous containment of the adhesive that solves the adhesive web/thread formation described above. It is further an objective of the present invention to provide a bonding system that ensures that only the areas desired to be covered by the adhesive (adhesive lay-down and shaping) are controlled more effectively than by means of traditional hot-gun application of hot-melt adhesives. It is yet another objective of the present invention to provide a bonding system that creates a very low profile and at the same time very durable bonding mechanism.